U.S. Expanded Risk-Based Approach (ERBA) & AOCI Unrealized Securities Filter Removal

Jointly developed by the U.S. Federal Reserve System, the OCC, and the FDIC to transpose Basel III Endgame into 12 CFR Part 217, the Expanded Risk-Based Approach (ERBA) overhauls capital measurement for U.S. banking organizations with USD 100 billion or more in consolidated assets. Tracked in the ERBA 2026 Benchmark Standard, the framework replaces credit and operational internal models with risk-sensitive standardized schedules while eliminating the Accumulated Other Comprehensive Income (AOCI) capital opt-out that masked unrealized securities losses prior to March 2023.

Elimination of Credit IRB Models and the Dual-Stack U.S. Collins Architecture#

Unlike EU CRR III—which preserves Foundation and Retail IRB subject to the BCBS d424 72.5% RWA output floor—the U.S. ERBA architecture retires Advanced Approaches internal credit risk models altogether in favor of granular standardized risk-weight schedules, FRTB market risk, SA-CCR derivatives exposure, BA-CVA/SA-CVA, and SMA operational risk.

Because Section 171 of the Dodd-Frank Act prohibits risk-based capital requirements from falling below generally applicable U.S. Standardized Approach RWA, covered institutions such as Bank of America, Ally Financial, and American Express must maintain dual reporting engines—calculating capital ratios against both Legacy U.S. Standardized RWA and ERBA RWA, with the lower resulting CET1 ratio governing compliance.

Repeal of the Category III and IV AOCI Filter on Available-for-Sale Debt#

Under the 2019 U.S. Tailoring Rules, Category III and IV regional banks ($100B–$700B in assets) were permitted to make a one-time irrevocable election excluding unrealized gains and losses on Available-for-Sale (AFS) fixed-income portfolios from regulatory CET1. When policy interest rates rose 500+ basis points in 2022–2023, several regional lenders reported 10%–12% regulatory CET1 despite holding unrealized AFS and HTM duration losses exceeding half their tangible common equity.

Requiring AOCI flow-through aligns Category III and IV firms with Category I and II G-SIBs and international CET1 CAP30 deduction rules. Every 100 bps parallel upward shift in Treasury and agency MBS yields directly reduces regulatory CET1 by Duration x Portfolio_MV x (1 - Tax_Rate) unless hedged via pay-fixed interest rate swaps under ASC 815.

Calibration Shifts From the Original 2023 NPR to the Re-Proposed Endgame Consensus#

The initial July 2023 Notice of Proposed Rulemaking estimated a 16%–19% aggregate CET1 requirement increase for Category I and II G-SIBs, driven by gold-plated residential mortgage add-ons (+20 percentage points over BCBS CRE20), punitive tax-equity 400% weights, and fee-heavy SMA operational risk charges on wealth-management and card issuers like American Express.

Subsequent supervisory recalibrations signaled by Federal Reserve leadership trimmed the aggregate Category I/II G-SIB capital increase toward ~9% (~4.8% RWA/CET1 shift for diversified banks) and scaled back Category III/IV coverage primarily to AOCI recognition and targeted trading-book updates—preserving mortgage LTV alignment with international BCBS bands as summarized in our Basel III Endgame & CET1 cornerstone guide.

Interaction Between ERBA Risk Weights and the Dynamic Stress Capital Buffer (SCB)#

A foundational structural tension in U.S. capital regulation is the risk of double-counting credit, market, and operational shocks across both Pillar 1 ERBA risk weights and the Federal Reserve’s annual CCAR Stress Capital Buffer (SCB) nine-quarter depletion. Under Legacy Standardized RWA, static Pillar 1 lacks an explicit operational risk or trading-book stress component, whereas CCAR’s Global Market Shock and operational loss projections sit inside SCB; migrating to ERBA plus FRTB/SMA necessitates offsetting SCB recalibration so identical fee and trading exposures are not capitalized twice.

Securities Portfolio Duration Management and HTM Reclassification Limits#

Once AOCI flows into CET1, bank ALCO committees cannot freely escape mark-to-market capital volatility simply by shifting AFS bonds into Held-to-Maturity (HTM). Reclassifying underwater AFS bonds to HTM freezes existing unrealized losses in AOCI (amortizing them concurrently with the bond discount over remaining life), while selling even a small slice of HTM securities triggers ASC 320 HTM tainting prohibitions across the Basel III Endgame & Capital Ratios topic hub.